(n.) The hairy or feathery appendage of the achenes of thistles, dandelions, and most other plants of the order Compositae; also, the scales, awns, or bristles which represent the calyx in other plants of the same order.
Example Sentences:
(1) In a series of in virtro experiments (n = 64) using the mature flowers or seeds and pappus hairs of Karoo bushes Chrysocoma ciliata, Dimorphotheca cuneata, Eriocephalus ericoides, Gazania krebsiana and Gnidia polycephala, small phytobezoars were formed from material of E. ericoides, G. krebsiana and G. polycephala either alone or in combinations.
(2) In a small in vivo trial, 4 groups of one sheep and one goat each were fed 10% of either C. ciliata, E. ericoides, G. polycephala seeds and pappus hairs, or a mixture of all 3, added to a basal diet of milled lucerne fed for up to 31 d. Small phytobezoars were formed in the goats but not the sheep receiving C. ciliata, and G. polycephala material.
(3) Of particular interest was the presence of annular thickenings as well as terminal hooks on both bezoar fibres and pappus hairs, both of which structures are believed to be involved in the formation of bezoars.
(4) The chemical composition of bezoars found in goats and sheep, resembled that of pappus hairs and stems of the Karoo bushes Eriocephalus ericoides and Gnidia polycephala more closely than that of mohair.
(5) This close similarity between the fibres in bezoars and those of pappus hairs in the 3 plant species studied, leads to the conclusion that the bezoars consisted largely of pappus hairs of these and possibly other species.
(6) The microscopic structure and ultrastructure of these pappus hairs moreover closely resembled the fibres of bezoars but were quite distinct from that of hair or wool.
(7) These diameters were very similar to those of the pappus hairs surrounding the seeds of the Karoo bushes Chrysocoma ciliata, Eriocephalus ericoides and Gnidia polycephala (means of 6.06 microns, 16.67 microns and 22.73 microns respectively).
Sepal
Definition:
(n.) A leaf or division of the calyx.
Example Sentences:
(1) In agamous-1, stamens to petals; in apetala2-1, sepals to leaves and petals to staminoid petals; in apetala3-1, petals to sepals and stamens to carpels; in pistillata-1, petals to sepals.
(2) The PR-1 class of proteins (biological function unknown) is located in sepal tissue.
(3) Sepal primordia then arise (stage 3) and grow to overlie the primordium (stage 4).
(4) In the families of flowering plants in which these organs occur, they are patterned with the sepals in the outermost whorl or whorls of the flower, with the petals next closest to the center, the stamens even closer to the center, and the carpels central.
(5) In flowers, expression was observed in sepals, anthers, and carpels, but not in petals.
(6) LAT52 mRNA is not detectable in pistils, sepals or non-reproductive tissues.
(7) Mutation of this gene (defA-1) causes homeotic transformation of petals into sepals and of stamina into carpels in flowers displaying the 'globifera' phenotype, as shown by cross sections and scanning electronmicroscopy of developing flowers.
(8) In ag mutants, the loss of AG function leads to the conversion of these organs to the perianth organs (petals and sepals).
(9) We found that AG RNA is present in the stamen and carpel primordia but is undetectable in sepal and petal primordia throughout early wild-type flower development, consistent with the mutant phenotype.
(10) New mutations at the APETALA2 locus, ap2-2, ap2-8 and ap2-9, cause homeotic conversions in the outer two whorls: sepals to carpels (or leaves) and petals to stamens.
(11) Comparative studies between two pea cultivars, one with a high incidence of seed transmission and one with none, showed that PSbMV infected the floral tissues (sepals, petals, anther and carpel) of both cultivars, but was not detected in ovules prior to fertilization.
(12) We also showed that both promoters can function independently and that the chiA PA1 promoter is expressed in limb (epidermal and parenchyma cells), tube (inner epidermal and parenchyma cells), seed (seed coat, endosperm, and embryo), sepal, leaf, and stem.
(13) The distribution of beta-glucuronidase activity in these transgenic plants is very similar to that of endogenous PAL2 transcripts in bean, with very high levels in petals; marked accumulation in anthers, stigmas, roots, and shoots; and low levels in sepals, ovaries, and leaves.
(14) Mutations in the APETALA3 (AP3) gene of A. thaliana result in homeotic transformations of petals to sepals and stamens to carpels.
(15) Its expression is greater than 50-fold higher in sepals and greater than 500-fold higher in the rest of the flower than in leaves or roots.
(16) Upon mutation of the gene, petals are transformed to sepals and stamens to carpels, indicating that deficiens is essential for the activation of genes required for petal and stamen formation.
(17) Transcripts are present in petals, stamens and pistil but are not detectable in sepals.
(18) However, PR-2 polypeptides were observed only in sepal tissue.
(19) AP2 is a floral homeotic gene that is necessary for the normal development of sepals and petals in floral whorls 1 and 2.
(20) The fbp2 gene is expressed in petals, stamen, carpels, and at a very low level in sepals but not in vegetative tissues.